1. Field of the Invention
The present invention relates in general to lubricating devices for an automatic power transmission and more particularly to lubricating devices for a planetary gear unit of an automatic power transmission that has a specified operation mode wherein when revolution of a pinion carrier is stopped under operation of an associated engine, pinions carried by the pinion carrier and a ring gear meshed with the pinions are rotated.
2. Description of the Related Art
Laid-open Japanese Patent Application (Tokkaihei) 07-208586 shows a lubricating device for a planetary gear unit of an automatic power transmission of the above-mentioned type. The automatic power transmission has such a structure that a pinion carrier rotatably held in the transmission holds pinion shafts that hold pinions and a ring gear is meshed with the pinions. In such structure, a sufficient lubrication is needed by the pinions as well as a ring gear bearing rotatably supporting the ring gear in order to avoid undesired seizing of the pinions, the ring gear bearing and their associated parts. The published Application shows a lubricating device that is constructed to feed the pinions, the ring gear bearing and their associated parts with a lubrication oil throughout all speeds with the aid of an oil pumping function of an output member that is constantly rotated except at stopping of an associated engine.